Originally Posted by csprague
I would first replace the bulb and then if that doesn't work check the wiring. I'm guess its an old bulb though and that's the culprit.
I don't think it would be an old bulb because it does it constantly with the same variables. If it was an old bulb it would just be dim or work randomly, unless you had a bulb like mine where if you flick it, it will work.